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Bonier F. Future directions in urban endocrinology - The effects of endocrine plasticity on urban tolerance. Mol Cell Endocrinol 2023; 565:111886. [PMID: 36775244 DOI: 10.1016/j.mce.2023.111886] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/12/2023]
Abstract
After twenty years of studies of endocrine traits in animals living in cities, the field of urban endocrinology has built a robust literature including numerous studies looking for signatures of the effects of urban living, usually in mean circulating hormone concentrations. The findings of this past research have primarily demonstrated the absence of any generalizable endocrine responses to city life. In this opinion paper, I suggest that a strong route forward would include investigations of the role of variation in endocrine plasticity in determining the degree to which organisms tolerate urban challenges (i.e., urban tolerance). Achieving this research aim will require creative experimental and comparative studies, consideration of alternative study systems, and teasing apart of sources of variation in plastic phenotypes (plasticity, sorting, and contemporary evolution). Insight into the role of endocrine plasticity in influencing urban tolerance could help us better understand and predict impacts of expanding urbanization on biodiversity across the globe.
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Affiliation(s)
- Frances Bonier
- Department of Biology, Queen's University, Kingston, ON, K7L 3N6, Canada.
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2
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Bentz AB, Empson TA, George EM, Rusch DB, Buechlein A, Rosvall KA. How experimental competition changes ovarian gene activity in free-living birds: Implications for steroidogenesis, maternal effects, and beyond. Horm Behav 2022; 142:105171. [PMID: 35381449 DOI: 10.1016/j.yhbeh.2022.105171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/11/2022] [Accepted: 03/23/2022] [Indexed: 11/04/2022]
Abstract
The ovary plays an important role in mediating both a female's response to her social environment and communicating it to her developing offspring via maternal effects. Past work has focused on how ovarian hormones respond to competition, but we know little about how the broader ovarian transcriptomic landscape changes, either during or after competition, giving us a narrow perspective on how socially induced phenotypes arise. Here, we experimentally generated social competition among wild, cavity-nesting female birds (tree swallows, Tachycineta bicolor), a species in which females lack a socially induced rise in circulating testosterone but they nevertheless increase allocation to eggs. After territory settlement, we reduced availability of nesting cavities, generating heightened competition; within 24 h we reversed the manipulation, causing aggressive interactions to subside. We measured ovarian transcriptomic responses at the peak of competition and 48 h later, along with date-matched controls. Network analyses indicated that competing females experienced an immediate and temporary decrease in the expression of genes involved in the early stages of steroidogenesis, and this was moderately correlated with plasma testosterone; however, two days after competition had ended, there was a marked increase in the expression of genes involved in the final stages of steroidogenesis, including HSD17B1. Gene networks related to the cell cycle, muscle performance, and extracellular matrix organization also displayed altered activity. Although the functional consequences of these findings are unclear, they shed light on socially responsive ovarian genomic mechanisms that could potentially exert lasting effects on behavior, reproduction, and maternal effects.
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Affiliation(s)
- Alexandra B Bentz
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Department of Biology, University of Oklahoma, Norman, OK 73019, USA.
| | - Tara A Empson
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
| | - Elizabeth M George
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Department of Biology, Texas A&M University, College Station, TX, 77843, USA
| | - Douglas B Rusch
- Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN, USA
| | - Aaron Buechlein
- Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN, USA
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3
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Nine Levels of Explanation : A Proposed Expansion of Tinbergen's Four-Level Framework for Understanding the Causes of Behavior. HUMAN NATURE-AN INTERDISCIPLINARY BIOSOCIAL PERSPECTIVE 2021; 32:748-793. [PMID: 34739657 DOI: 10.1007/s12110-021-09414-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/23/2021] [Indexed: 01/16/2023]
Abstract
Tinbergen's classic "On Aims and Methods of Ethology" (Zeitschrift für Tierpsychologie, 20, 1963) proposed four levels of explanation of behavior, which he thought would soon apply to humans. This paper discusses the need for multilevel explanation; Huxley and Mayr's prior models, and others that followed; Tinbergen's differences with Lorenz on "the innate"; and Mayr's ultimate/proximate distinction. It synthesizes these approaches with nine levels of explanation in three categories: phylogeny, natural selection, and genomics (ultimate causes); maturation, sensitive period effects, and routine environmental effects (intermediate causes); and hormonal/metabolic processes, neural circuitry, and eliciting stimuli (proximate causes), as a respectful extension of Tinbergen's levels. The proposed classification supports and builds on Tinbergen's multilevel model and Mayr's ultimate/proximate continuum, adding intermediate causes in accord with Tinbergen's emphasis on ontogeny. It requires no modification of Standard Evolutionary Theory or The Modern Synthesis, but shows that much that critics claim was missing was in fact part of Neo-Darwinian theory (so named by J. Mark Baldwin in The American Naturalist in 1896) all along, notably reciprocal causation in ontogeny, niche construction, cultural evolution, and multilevel selection. Updates of classical examples in ethology are offered at each of the nine levels, including the neuroethological and genomic findings Tinbergen foresaw. Finally, human examples are supplied at each level, fulfilling his hope of human applications as part of the biology of behavior. This broad ethological framework empowers us to explain human behavior-eventually completely-and vindicates the idea of human nature, and of humans as a part of nature.
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4
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Explaining discrepancies in the study of maternal effects: the role of context and embryo. Curr Opin Behav Sci 2020. [DOI: 10.1016/j.cobeha.2020.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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5
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Sarraude T, Hsu BY, Groothuis T, Ruuskanen S. Testing the short-and long-term effects of elevated prenatal exposure to different forms of thyroid hormones. PeerJ 2020; 8:e10175. [PMID: 33088630 PMCID: PMC7571413 DOI: 10.7717/peerj.10175] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
Maternal thyroid hormones (THs) are known to be crucial in embryonic development in humans, but their influence on other, especially wild, animals remains poorly understood. So far, the studies that experimentally investigated the consequences of maternal THs focused on short-term effects, while early organisational effects with long-term consequences, as shown for other prenatal hormones, could also be expected. In this study, we aimed at investigating both the short- and long-term effects of prenatal THs in a bird species, the Japanese quail Coturnix japonica. We experimentally elevated yolk TH content (the prohormone T4, and its active metabolite T3, as well as a combination of both hormones). We analysed hatching success, embryonic development, offspring growth and oxidative stress as well as their potential organisational effects on reproduction, moult and oxidative stress in adulthood. We found that eggs injected with T4 had a higher hatching success compared with control eggs, suggesting conversion of T4 into T3 by the embryo. We detected no evidence for other short-term or long-term effects of yolk THs. These results suggest that yolk THs are important in the embryonic stage of precocial birds, but other short- and long-term consequences remain unclear. Research on maternal THs will greatly benefit from studies investigating how embryos use and respond to this maternal signalling. Long-term studies on prenatal THs in other taxa in the wild are needed for a better understanding of this hormone-mediated maternal pathway.
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Affiliation(s)
- Tom Sarraude
- Department of Biology, University of Turku, Turku, Finland.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Bin-Yan Hsu
- Department of Biology, University of Turku, Turku, Finland
| | - Ton Groothuis
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Suvi Ruuskanen
- Department of Biology, University of Turku, Turku, Finland
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6
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Fresneau N, Estramil N, Müller W. Are offspring begging levels exaggerated beyond the parental optimum? Evidence from a bidirectional selection experiment. J Evol Biol 2020; 33:899-910. [PMID: 32236996 DOI: 10.1111/jeb.13621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/15/2020] [Indexed: 11/29/2022]
Abstract
Parental care involves elaborate behavioural interactions between parents and their offspring, with offspring stimulating their parents via begging to provision resources. Thus, begging has direct fitness benefits as it enhances offspring growth and survival. It is nevertheless subject to a complex evolutionary trajectory, because begging may serve as a means for the offspring to manipulate parents in the context of evolutionary conflicts of interest. Furthermore, it has been hypothesized that begging is coadapted and potentially genetically correlated with parental care traits as a result of social selection. Further experiments on the causal processes that shape the evolution of begging are therefore essential. We applied bidirectional artificial selection on begging behaviour, using canaries (Serinus canaria) as a model species. We measured the response to selection, the consequences for offspring development, changes in parental care traits, here the rate of parental provisioning, as well as the effects on reproductive success. After three generations of selection, offspring differed in begging behaviour according to our artificial selection regime: nestlings of the high begging line begged significantly more than nestlings of the low begging line. Intriguingly, begging less benefitted the nestlings, as reflected by on average significantly higher growth rates, and increased reproductive success in terms of a higher number of fledglings in the low selected line. Begging could thus represent an exaggerated trait, possibly because parent-offspring conflict enhanced the selection on begging. We did not find evidence that we co-selected on parental provisioning, which may be due to the lack of power, but may also suggest that the evolution of begging is probably not constrained by a genetic correlation between parental provisioning and offspring begging.
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Affiliation(s)
- Nolwenn Fresneau
- MTA-PE Evolutionary Ecology Research Group, University of Pannonia, Veszprém, Hungary.,Department of Limnology, University of Pannonia, Veszprém, Hungary.,Behavioural Ecology and Ecophysiology Research Group, Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Natalia Estramil
- Behavioural Ecology and Ecophysiology Research Group, Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Wendt Müller
- Behavioural Ecology and Ecophysiology Research Group, Department of Biology, University of Antwerp, Wilrijk, Belgium
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7
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Partecke J, Hegyi G, Fitze PS, Gasparini J, Schwabl H. Maternal effects and urbanization: Variation of yolk androgens and immunoglobulin in city and forest blackbirds. Ecol Evol 2020; 10:2213-2224. [PMID: 32128150 PMCID: PMC7042752 DOI: 10.1002/ece3.6058] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 11/22/2019] [Accepted: 01/08/2020] [Indexed: 12/21/2022] Open
Abstract
Wildlife inhabiting urban environments exhibit drastic changes in morphology, physiology, and behavior. It has often been argued that these phenotypic responses could be the result of micro-evolutionary changes following the urbanization process. However, other mechanisms such as phenotypic plasticity, maternal effects, and developmental plasticity could be involved as well. To address maternal effects as potential mechanisms, we compared maternal hormone and antibody concentrations in eggs between city and forest populations of European blackbirds (Turdus merula), a widely distributed species for which previous research demonstrated differences in behavioral and physiological traits. We measured egg and yolk mass, yolk concentrations of androgens (androstenedione [A4], testosterone [T], 5α-dihydrotestosterone [5α-DHT], and immunoglobulins [IgY]) and related them to population, clutch size, laying order, embryo sex, and progress of breeding season. We show (a) earlier onset of laying in the city than forest population, but similar egg and clutch size; (b) higher overall yolk androgen concentrations in the forest than the city population (sex-dependent for T); (c) greater among-female variation of yolk T and 5α-DHT concentrations in the forest than city population, but similar within-clutch variation; (d) similar IgY concentrations with a seasonal decline in both populations; and (e) population-specific positive (city) or negative (forest) association of yolk A4 and T with IgY concentrations. Our results are consistent with the hypotheses that hormone-mediated maternal effects contribute to differences in behavioral and physiological traits between city and forest individuals and that yolk androgen and immunoglobulin levels can exhibit population-specific relationships rather than trade-off against each other.
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Affiliation(s)
- Jesko Partecke
- Department of MigrationMax Planck Institute of Animal BehaviorRadolfzellGermany
- Department of BiologyUniversity of KonstanzKonstanzGermany
- School of Biological Sciences and Center for Reproductive BiologyWashington State University PullmanPullmanWAUSA
| | - Gergely Hegyi
- School of Biological Sciences and Center for Reproductive BiologyWashington State University PullmanPullmanWAUSA
- Department of Systematic Zoology and EcologyEötvös Loránd UniversityBudapestHungary
| | | | - Julien Gasparini
- Sorbonne UniversitéUPECCNRSINRAIRDInstitut d'Ecologie et des Sciences de l'Environnement de ParisParisFrance
| | - Hubert Schwabl
- School of Biological Sciences and Center for Reproductive BiologyWashington State University PullmanPullmanWAUSA
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8
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Jenni-Eiermann S, Jenni L, Olano Marin J, Homberger B. Seasonal changes in yolk hormone concentrations carry-over to offspring traits. Gen Comp Endocrinol 2020; 287:113346. [PMID: 31790656 DOI: 10.1016/j.ygcen.2019.113346] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/21/2019] [Accepted: 11/26/2019] [Indexed: 11/24/2022]
Abstract
Yolk hormones are substances which transmit non-genetic factors from the mother to the next generation. The systematic changes of yolk hormone concentrations within asynchronously hatching clutches have been interpreted as a means to adaptively shape the offspring's phenotype. However, in synchronously hatching clutches the role of yolk hormones is less understood. We investigated whether seasonal changes between eggs in the yolk hormones testosterone (Testo), progesterone (Prog) and corticosterone (Cort) also occur in the grey partridge, a synchronously hatching precocial species without direct food competition between siblings. Specifically we asked whether yolk hormone concentrations systematically vary with season and whether they affect the offspring's hatching mass, mass gain, circulating baseline and stress-induced Cort. Additionally, we investigated the effect of genetic background and food availability on yolk hormone concentrations by subjecting grey partridge hens of two strains (wild and domesticated) to two different feeding regimes (predictable vs. unpredictable feeding) during egg laying. We hypothesized that egg hormone concentrations change over the season, but breeding in captivity over many generations and ad libitum food access could have resulted in domestication effects which abolished potential seasonal effects. Results showed that progressing season had a strong positive effect on yolk Prog and yolk Testo, but not on yolk Cort. Feeding regimes and strain had no effect on yolk hormones. Offspring mass and mass gain increased and baseline Cort decreased with progressing season. In addition, yolk Testo correlated positively with offspring mass gain and negatively with baseline Cort, while yolk Prog had a positive correlation with baseline Cort. Strain and feeding regimes of the mother had no effect on offspring traits. In conclusion, grey partridge chicks hatching late in the season might benefit from the increased concentrations of the growth-stimulating yolk Testo and by this catch-up in development. Hence, yolk hormone concentration could adaptively shape the offspring phenotype in a precocial species.
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Affiliation(s)
| | - Lukas Jenni
- Swiss Ornithological Institute, Seerose 1, 6204 Sempach, Switzerland
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9
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Ledecka D, Zeman M, Okuliarova M. Genetic variation in maternal yolk testosterone allocation predicts female mating decisions in Japanese quail. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.08.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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10
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Urvik J, Rattiste K, Giraudeau M, Okuliarová M, Hõrak P, Sepp T. Age-specific patterns of maternal investment in common gull egg yolk. Biol Lett 2019; 14:rsbl.2018.0346. [PMID: 29997189 DOI: 10.1098/rsbl.2018.0346] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/19/2018] [Indexed: 01/19/2023] Open
Abstract
While the general patterns of age-specific changes in reproductive success are quite well established in long-lived animals, we still do not know if allocation patterns of maternally transmitted compounds are related to maternal age. We measured the levels of yolk testosterone, carotenoids and vitamins A and E in a population of known-aged common gulls (Larus canus) and found an age-specific pattern in yolk lutein and vitamin A concentrations. Middle-aged mothers allocated more of these substances to yolk compared to young and old mothers. These results can be explained through differences in age-specific foraging, absorption or deposition patterns of carotenoids and vitamins into yolk. If these molecules play a role in antioxidant defence and immune modulation, our results suggest a possible physiological pathway underlying the age-specific changes in reproductive success of long-lived birds in the wild.
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Affiliation(s)
- Janek Urvik
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Kalev Rattiste
- Chair of Biodiversity and Nature Tourism, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, 51006, Tartu, Estonia
| | - Mathieu Giraudeau
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9FE, UK
| | - Monika Okuliarová
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15, Bratislava, Slovakia
| | - Peeter Hõrak
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Tuul Sepp
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
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11
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Lelono A, Riedstra B, Groothuis T. Ejaculate testosterone levels affect maternal investment in red junglefowl (Gallus gallus gallus). Sci Rep 2019; 9:12126. [PMID: 31431647 PMCID: PMC6702165 DOI: 10.1038/s41598-019-48563-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 08/05/2019] [Indexed: 12/11/2022] Open
Abstract
Substantial concentrations of testosterone are not only present in a male’s circulation, but also in its ejaculate. Surprisingly, the regulation of ejaculate T and its effects on females and their offspring, potentially a cryptic paternal trait, are not known. We found lower circulating and higher ejaculate T concentrations in subordinate red junglefowl (Gallus gallus gallus) males compared to dominant males, suggestive of an adaptive trade-off in T allocation to circulation and their ejaculate. Subsequently, we artificially inseminated females with either testosterone enriched (TE) or control ejaculates (CE) in a cross-over design. TE females produced heavier eggs than CE females. Offspring growth and tonic immobility were affected in a sex-specific way by TE. TE sons were heavier with shorter TI duration than CE sons, and TE daughters were lighter than CE daughters but daughters did not differ in TI score. However, the chicks competitiveness was not influenced by the TE nor CE. This indicates a previously unknown function of ejaculate testosterone as well as a new form of interaction between a cryptic paternal trait and a maternal effect that may be widespread in the animal kingdom.
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Affiliation(s)
- Asmoro Lelono
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands. .,Department of Biology, Faculty of Mathematics and Natural Sciences, University of Jember, 68121, Jember, East Java, Indonesia.
| | - Bernd Riedstra
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Ton Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
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12
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Hsu BY, Verhagen I, Gienapp P, Darras VM, Visser ME, Ruuskanen S. Between- and Within-Individual Variation of Maternal Thyroid Hormone Deposition in Wild Great Tits ( Parus major). Am Nat 2019; 194:E96-E108. [PMID: 31490720 DOI: 10.1086/704738] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Maternal hormones are often considered a mediator of anticipatory maternal effects; namely, mothers adjust maternal hormone transfer to prepare the offspring for the anticipated environment. The flexibility for mothers to adjust hormone transfer is therefore a prerequisite for such anticipatory maternal effects. Nevertheless, previous studies have focused only on the average differences of maternal hormone transfer between groups and neglected the substantial individual variation, despite the fact that individual plasticity in maternal hormone transfer is actually the central assumption. In this study, we studied the between- and within-individual variation of maternal thyroid hormones (THs) in egg yolk of wild great tits (Parus major) and estimated the individual plasticity of maternal yolk THs across environmental temperature, clutch initiation dates, and egg laying order using linear mixed effects models. Interestingly, our models provide statistical evidence that the two main THs-the main biologically active hormone T3 and T4, which is mostly considered a prohormone-exhibited different variation patterns. Yolk T3 showed significant between-individual variation on the average levels, in line with its previously reported moderate heritability. Yolk T4, however, showed significant between-clutch variation in the pattern over the laying sequence, suggesting a great within-individual plasticity. Our findings suggest that the role and function of the hormone within the endocrine axis likely influences its flexibility to respond to environmental change. Whether the flexibility of T4 deposition brings a fitness advantage should be examined along with its potential effects on offspring, which remain to be further investigated.
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Groothuis TGG, Hsu BY, Kumar N, Tschirren B. Revisiting mechanisms and functions of prenatal hormone-mediated maternal effects using avian species as a model. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180115. [PMID: 30966885 PMCID: PMC6460091 DOI: 10.1098/rstb.2018.0115] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2018] [Indexed: 12/16/2022] Open
Abstract
Maternal effects can adaptively modulate offspring developmental trajectories in variable but predictable environments. Hormone synthesis is sensitive to environmental factors, and maternal hormones are thus a powerful mechanism to transfer environmental cues to the next generation. Birds have become a key model for the study of hormone-mediated maternal effects because the embryo develops outside the mother's body, facilitating the measurement and manipulation of prenatal hormone exposure. At the same time, birds are excellent models for the integration of both proximate and ultimate approaches, which is key to a better understanding of the evolution of hormone-mediated maternal effects. Over the past two decades, a surge of studies on hormone-mediated maternal effects has revealed an increasing number of discrepancies. In this review, we discuss the role of the environment, genetic factors and social interactions in causing these discrepancies and provide a framework to resolve them. We also explore the largely neglected role of the embryo in modulating the maternal signal, as well as costs and benefits of hormone transfer and expression for the different family members. We conclude by highlighting fruitful avenues for future research that have opened up thanks to new theoretical insights and technical advances in the field. This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.
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Affiliation(s)
- Ton G. G. Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Bin-Yan Hsu
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
- Department of Biology, University of Turku, Turku, Finland
| | - Neeraj Kumar
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Barbara Tschirren
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
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14
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Hoi H, Darolová A, Krištofík J, Poláček M, Majtán J, Zeman M, Okuliarová M, Turčoková L, Knauer F. Covariation between eggshell colouration and eggshell bacteria abundance and egg characteristics in blackbirds. ETHOL ECOL EVOL 2019. [DOI: 10.1080/03949370.2019.1575910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Herbert Hoi
- Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Savoyenstrasse 1a, 1160 Vienna, Austria
| | - Alžbeta Darolová
- Department of Animal Ecology, Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 06 Bratislava, Slovakia
| | - Ján Krištofík
- Department of Animal Ecology, Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 06 Bratislava, Slovakia
| | - Miroslav Poláček
- Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Savoyenstrasse 1a, 1160 Vienna, Austria
| | - Juraj Majtán
- Department of Microbiology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 06 Bratislava, Slovakia
| | - Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Monika Okuliarová
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Lucia Turčoková
- Department of Zoology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Felix Knauer
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstrasse 1, 1160 Vienna, Austria
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15
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Okuliarova M, Meddle SL, Zeman M. Egg deposition of maternal testosterone is primarily controlled by the preovulatory peak of luteinizing hormone in Japanese quail. Gen Comp Endocrinol 2018; 256:23-29. [PMID: 28495270 PMCID: PMC5771469 DOI: 10.1016/j.ygcen.2017.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 03/27/2017] [Accepted: 05/06/2017] [Indexed: 01/13/2023]
Abstract
Differential transfer of maternal testosterone (T) into egg yolk provides a means of adjusting an offspring's phenotype to ambient environmental conditions. While the environmental and genetic driven variability in yolk T levels is widely described, the underlying mechanisms are poorly understood. Here, we investigated whether neuroendocrine mechanisms controlling ovulatory processes are associated with the regulation of yolk T deposition. Circulatory profiles of luteinizing hormone (LH), T and estradiol levels were analysed during the last 7h before ovulation in Japanese quail selected for contrasting yolk T concentrations. Moreover, the pituitary responsiveness to a single challenge with gonadotropin releasing hormone (GnRH) was evaluated. High egg T (HET) birds displayed higher concentrations of LH at 3.5h before ovulation than low egg T (LET) birds while no differences were found around the time of expected ovulation. The pre-ovulatory profile of T and estradiol levels did not differ between LET and HET females but pre-ovulatory plasma T positively correlated with LH concentrations at 6.5h and 3.5h before ovulation. The LH response to GnRH did not differ between LET and HET females. Our results demonstrate that the pre-ovulatory LH surge can determine the amount of T transferred into the egg yolk. This link between yolk T deposition and the ovulatory cycle driven variation of reproductive hormones may explain balance between the effects of circulating T on female's reproductive physiology and yolk T on offspring phenotype.
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Affiliation(s)
- Monika Okuliarova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
| | - Simone L Meddle
- The Roslin Institute, The Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush, UK
| | - Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic; Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Ivanka pri Dunaji, Slovak Republic
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16
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Kankova Z, Zeman M, Ledecka D, Okuliarova M. Variable effects of elevated egg yolk testosterone on different arms of the immune system in young quail. Gen Comp Endocrinol 2018; 256:30-36. [PMID: 28736225 DOI: 10.1016/j.ygcen.2017.07.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/29/2017] [Accepted: 07/16/2017] [Indexed: 11/25/2022]
Affiliation(s)
- Zuzana Kankova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia; Centre of Biosciences, Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia.
| | - Daniela Ledecka
- Centre of Biosciences, Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Monika Okuliarova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
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17
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Ruuskanen S, Groothuis TGG, Baugh AT, Schaper SV, Vries B, Oers K. Maternal egg hormones in the mating context: The effect of pair personality. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12987] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Suvi Ruuskanen
- Section of EcologyDepartment of BiologyUniversity of Turku Turku Finland
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW) Wageningen The Netherlands
| | - Ton G. G. Groothuis
- Groningen Institute for Evolutionary Life SciencesUniversity of Groningen Groningen The Netherlands
| | | | - Sonja V. Schaper
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW) Wageningen The Netherlands
| | - Bonnie Vries
- Groningen Institute for Evolutionary Life SciencesUniversity of Groningen Groningen The Netherlands
| | - Kees Oers
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW) Wageningen The Netherlands
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18
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Estramil N, Groothuis TGG, Eens M, de Vries B, Müller W. Coadaptation of offspring begging and parental provisioning: A role for prenatal maternal effects? Horm Behav 2017; 87:129-136. [PMID: 27838359 DOI: 10.1016/j.yhbeh.2016.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 11/02/2016] [Accepted: 11/03/2016] [Indexed: 11/30/2022]
Abstract
Recent studies on birds have shown that offspring begging and parental provisioning covary at the phenotypic level, which is thought to reflect genetic correlations. However, prenatal maternal factors, like yolk testosterone, may also facilitate parent-offspring coadaptation via their effects on offspring begging and development. In fact, maternal effects are thought to adjust offspring phenotype to the environmental conditions they will experience after birth, which are in turn strongly dependent on the levels of parental provisioning. Using cross-fostering experiments in canaries, we tested the role of maternal effects on parent-offspring coadaptation from two different approaches. First, we analyzed whether females deposit yolk testosterone in relation to their own or their partner's prospective parental provisioning, measured as the rate of parental feeding to foster nestlings. Second, we investigated whether females deposit yolk testosterone in relation to costs they incurred when raising a previous brood, as this likely impinges on their capacity to provide parental care in the near future. However, from the results of both experiments we have no evidence that canary females deposit yolk testosterone in order to match offspring begging to the levels of care they and/or their partners provide. We therefore found no evidence that yolk testosterone facilitates parent-offspring coadaptation. In addition, our results suggest that the functional consequences of yolk testosterone deposition may relate to hatching asynchrony since it primarily varied with egg laying order.
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Affiliation(s)
- Natalia Estramil
- Department of Biology-Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
| | - Ton G G Groothuis
- Behavioural Biology, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
| | - Marcel Eens
- Department of Biology-Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
| | - Bonnie de Vries
- Behavioural Biology, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
| | - Wendt Müller
- Department of Biology-Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
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19
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Bentz AB, Becker DJ, Navara KJ. Evolutionary implications of interspecific variation in a maternal effect: a meta-analysis of yolk testosterone response to competition. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160499. [PMID: 28018636 PMCID: PMC5180134 DOI: 10.1098/rsos.160499] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/02/2016] [Indexed: 05/02/2023]
Abstract
Competition between conspecifics during the breeding season can result in behavioural and physiological programming of offspring via maternal effects. For birds, in which maternal effects are best studied, it has been claimed that exposure to increased competition causes greater deposition of testosterone into egg yolks, which creates faster growing, more aggressive offspring; such traits are thought to be beneficial for high-competition environments. Nevertheless, not all species show a positive relationship between competitive interactions and yolk testosterone, and an explanation for this interspecific variation is lacking. We here test if the magnitude and direction of maternal testosterone allocated to eggs in response to competition can be explained by life-history traits while accounting for phylogenetic relationships. We performed a meta-analysis relating effect size of yolk testosterone response to competition with species coloniality, nest type, parental effort and mating type. We found that effect size was moderated by coloniality and nest type; colonial species and those with open nests allocate less testosterone to eggs when in more competitive environments. Applying a life-history perspective helps contextualize studies showing little or negative responses of yolk testosterone to competition and improves our understanding of how variation in this maternal effect may have evolved.
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Affiliation(s)
- Alexandra B. Bentz
- Poultry Science Department, University of Georgia, 203 Poultry Science Building, Athens, GA 30602, USA
| | - Daniel J. Becker
- Odum School of Ecology, University of Georgia, 140 E. Green Street, Athens, GA 30602, USA
| | - Kristen J. Navara
- Poultry Science Department, University of Georgia, 203 Poultry Science Building, Athens, GA 30602, USA
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20
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Pick JL, Ebneter C, Hutter P, Tschirren B. Disentangling Genetic and Prenatal Maternal Effects on Offspring Size and Survival. Am Nat 2016; 188:628-639. [PMID: 27860503 DOI: 10.1086/688918] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Organizational processes during prenatal development can have long-term effects on an individual's phenotype. Because these early developmental stages are sensitive to environmental influences, mothers are in a unique position to alter their offspring's phenotype by differentially allocating resources to their developing young. However, such prenatal maternal effects are difficult to disentangle from other forms of parental care, additive genetic effects, and/or other forms of maternal inheritance, hampering our understanding of their evolutionary consequences. Here we used divergent selection lines for high and low prenatal maternal investment and their reciprocal line crosses in a precocial bird-the Japanese quail (Coturnix japonica)-to quantify the relative importance of genes and prenatal maternal effects in shaping offspring phenotype. Maternal but not paternal origin strongly affected offspring body size and survival throughout development. Although the effects of maternal egg investment faded over time, they were large at key life stages. Additionally, there was evidence for other forms of maternal inheritance affecting offspring phenotype at later stages of development. Our study is among the first to successfully disentangle prenatal maternal effects from all other sources of confounding variation and highlights the important role of prenatal maternal provisioning in shaping offspring traits closely linked to fitness.
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21
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Tschirren B, Ziegler AK, Pick JL, Okuliarová M, Zeman M, Giraudeau M. Matrilineal inheritance of a key mediator of prenatal maternal effects. Proc Biol Sci 2016; 283:20161676. [PMID: 27629040 PMCID: PMC5031669 DOI: 10.1098/rspb.2016.1676] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 08/24/2016] [Indexed: 11/12/2022] Open
Abstract
Sex-linkage is predicted to evolve in response to sex-specific or sexually antagonistic selection. In line with this prediction, most sex-linked genes are associated with reproduction in the respective sex. In addition to traits directly involved in fertility and fecundity, mediators of maternal effects may be predisposed to evolve sex-linkage, because they indirectly affect female fitness through their effect on offspring phenotype. Here, we test for sex-linked inheritance of a key mediator of prenatal maternal effects in oviparous species, the transfer of maternally derived testosterone to the eggs. Consistent with maternal inheritance, we found that in Japanese quail (Coturnix japonica) granddaughters resemble their maternal (but not their paternal) grandmother in yolk testosterone deposition. This pattern of resemblance was not due to non-genetic priming effects of testosterone exposure during prenatal development, as an experimental manipulation of yolk testosterone levels did not affect the females' testosterone transfer to their own eggs later in life. Instead, W chromosome and/or mitochondrial variation may underlie the observed matrilineal inheritance pattern. Ultimately, the inheritance of mediators of maternal effects along the maternal line will allow for a fast and direct response to female-specific selection, thereby affecting the dynamics of evolutionary processes mediated by maternal effects.
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Affiliation(s)
- Barbara Tschirren
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Ann-Kathrin Ziegler
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Joel L Pick
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Monika Okuliarová
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
| | - Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
| | - Mathieu Giraudeau
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, UK
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22
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Ruuskanen S, Groothuis TGG, Schaper SV, Darras VM, de Vries B, Visser ME. Temperature-induced variation in yolk androgen and thyroid hormone levels in avian eggs. Gen Comp Endocrinol 2016; 235:29-37. [PMID: 27255366 DOI: 10.1016/j.ygcen.2016.05.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 05/20/2016] [Accepted: 05/29/2016] [Indexed: 11/26/2022]
Abstract
Global warming has substantially changed the environment, but the mechanisms to cope with these changes in animals, including the role of maternal effects, are poorly understood. Maternal effects via hormones deposited in eggs, have important environment-dependent effects on offspring development and fitness: thus females are expected to adjust these hormones to the environment, such as the ambient temperature. Longer-term temperature variation could function as a cue, predicting chick rearing conditions to which yolk hormone levels are adjusted, while short-term temperature variation during egg formation may causally affect hormone transfer to eggs. We studied the effects of ambient temperature on yolk androgens (testosterone and androstenedione) and thyroid hormones (thyroxine and triiodothyronine) in great tits (Parus major) using data from unmanipulated clutches from a wild population and from aviary birds (ad libitum food) exposed to different experimental temperature treatments during five years. Both in the wild and in captivity, longer-term pre-laying ambient temperature was not associated with clutch mean yolk hormone levels, while the way androstenedione and thyroxine levels varied across the laying sequence did associate with pre-laying temperature in the wild. Yolk testosterone levels were positively correlated with short-term temperature (during yolk formation) changes within clutches in both wild and captivity. We also report, for the first time in a wild bird, that yolk thyroxine levels correlated with a key environmental factor: thyroxine levels were negatively correlated with ambient temperature during egg formation. Thus, yolk hormone levels, especially testosterone, seem to be causally affected by ambient temperature. These short-term effects might reflect physiological changes in females with changes in ambient temperature. The adaptive value of the variation with ambient temperatures pre-laying or during egg formation should be studied with hormone manipulations in different thermal environments.
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Affiliation(s)
- Suvi Ruuskanen
- Section of Ecology, Department of Biology, University of Turku, Finland; Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), The Netherlands.
| | - Ton G G Groothuis
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands.
| | - Sonja V Schaper
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), The Netherlands.
| | - Veerle M Darras
- Laboratory of Comparative Endocrinology, Biology Department, KU Leuven, Belgium.
| | - Bonnie de Vries
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands.
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), The Netherlands.
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23
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Ruuskanen S, Gienapp P, Groothuis TGG, Schaper SV, Darras VM, Pereira C, de Vries B, Visser ME. Heritable variation in maternally derived yolk androgens, thyroid hormones and immune factors. Heredity (Edinb) 2016; 117:184-90. [PMID: 27381323 DOI: 10.1038/hdy.2016.49] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 04/29/2016] [Accepted: 05/08/2016] [Indexed: 11/10/2022] Open
Abstract
Maternal reproductive investment can critically influence offspring phenotype, and thus these maternal effects are expected to be under strong natural selection. Knowledge on the extent of heritable variation in the physiological mechanisms underlying maternal effects is however limited. In birds, resource allocation to eggs is a key mechanism for mothers to affect their offspring and different components of the egg may or may not be independently adjusted. We studied the heritability of egg components and their genetic and phenotypic covariation in great tits (Parus major), using captive-bred full siblings of wild origin. Egg mass, testosterone (T) and androstenedione (A4) hormone concentrations showed moderate heritability, in agreement with earlier findings. Interestingly, yolk triiodothyronine hormone (T3), but not its precursor, thyroxine hormone (T4), concentration was heritable. An immune factor, albumen lysozyme, showed moderate heritability, but yolk immunoglobulins (IgY) did not. The genetic correlation estimates were moderate but statistically nonsignificant; a trend for a positive genetic correlation was found between A4 and egg mass, T and lysozyme and IgY and lysozyme, respectively. Interestingly, phenotypic correlations were found only between A4 and T, and T4 and T3, respectively. Given that these egg components are associated with fitness-related traits in the offspring (and mother), and that we show that some components are heritable, it opens the possibility that natural selection may shape the rate and direction of phenotypic change via egg composition.
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Affiliation(s)
- S Ruuskanen
- Section of Ecology, Department of Biology, University of Turku, Turku, Finland.,Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - P Gienapp
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - T G G Groothuis
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - S V Schaper
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - V M Darras
- Laboratory of Comparative Endocrinology, Biology Department, KU Leuven, Leuven, Belgium
| | - C Pereira
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - B de Vries
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - M E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
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24
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Hsu BY, Dijkstra C, Groothuis TG. No escape from mother's will: effects of maternal testosterone on offspring reproductive behaviour far into adulthood. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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25
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Tschirren B, Ziegler AK, Canale CI, Okuliarová M, Zeman M, Giraudeau M. High Yolk Testosterone Transfer Is Associated with an Increased Female Metabolic Rate. Physiol Biochem Zool 2016; 89:448-52. [PMID: 27617364 DOI: 10.1086/687571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Yolk androgens of maternal origin are important mediators of prenatal maternal effects. Although in many species short-term benefits of exposure to high yolk androgen concentrations for the offspring have been observed, females differ substantially in the amount of androgens they transfer to their eggs. It suggests that costs for the offspring or the mother constrain the evolution of maternal hormone transfer. However, to date, the nature of these costs remains poorly understood. Unlike most previous work that focused on potential costs for the offspring, we here investigated whether high yolk testosterone transfer is associated with metabolic costs (i.e., a higher metabolic rate) for the mother. We show that Japanese quail (Coturnix japonica) females that deposit higher testosterone concentrations into their eggs have a higher resting metabolic rate. Because a higher metabolic rate is often associated with a shorter life span, this relationship may explain the negative association between yolk testosterone transfer and female longevity observed in the wild. Our results suggest that metabolic costs for the mother can balance the short-term benefits of yolk testosterone exposure for the offspring, thereby contributing to the maintenance of variation in maternal yolk hormone transfer in natural populations.
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26
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de Jong B, Lens L, Amininasab SM, van Oers K, Darras VM, Eens M, Pinxten R, Komdeur J, Groothuis TGG. Effects of experimentally sustained elevated testosterone on incubation behaviour and reproductive success in female great tits (Parus major). Gen Comp Endocrinol 2016; 230-231:38-47. [PMID: 26996426 DOI: 10.1016/j.ygcen.2016.02.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 02/10/2016] [Accepted: 02/16/2016] [Indexed: 11/27/2022]
Abstract
In many seasonally breeding birds, female and male testosterone (T) levels peak at the start of the breeding season, coinciding with pair bonding and nesting activities. Shortly after the onset of egg laying, T levels slowly decline to baseline levels in both sexes, but more rapidly so in females. During this period, T in males may still function to facilitate territorial behaviour, mate guarding and extra pair copulations, either via short lasting peaks or elevated basal levels of the hormone. In some species, however, males become insensitive to increased T after the onset of egg laying. It has been postulated that in these species bi-parental care is essential for offspring survival, as T is known to inhibit paternal care. However, only very few studies have analysed this for females. As females are heavily involved in parental care, they too might become insensitive to T after egg laying. Alternatively, because territorial defence, mate guarding and extra pair copulations are expected to be less important for females than for males, they may not have had the need to evolve a mechanism to become insensitive to T during the period of maternal care, because their natural T levels are never elevated during this part of the breeding season anyway. We tested these alternative hypotheses in female great tits (Parus major). Male great tits have previously been shown to be insensitive to T after egg laying with regard to nestling feeding behaviour (but not song rate). When females had started nest building, we experimentally elevated their T levels up to the nestling feeding phase, and measured incubation behaviour (only females incubate) and reproductive success. T did not significantly affect nest building or egg laying behaviour, although egg laying tended to be delayed in T females. Females with experimentally enhanced T maintained lower temperature during incubation but did not spend less time incubating. This might explain the reduced hatching success of their eggs, smaller brood size and lower number of fledglings we found in this study. As in this species T-dependent behaviour by females during the phase of parental care is not needed, the results support the hypothesis that in this species the need for selection in favour of T-insensitivity did not occur.
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Affiliation(s)
- Berber de Jong
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands; Terrestrial Ecology Unit, Department Biology, Ghent University, BE-9000 Ghent, Belgium; Behavioural and Physiological Ecology, Groningen Institute for ELIFES, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands.
| | - Luc Lens
- Terrestrial Ecology Unit, Department Biology, Ghent University, BE-9000 Ghent, Belgium
| | - Seyed Mehdi Amininasab
- Behavioural and Physiological Ecology, Groningen Institute for ELIFES, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands; Department of Environmental Science, Behbahan Khatam Alanbia University of Technology, Iran
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
| | - Veerle M Darras
- Laboratory of Comparative Endocrinology, K.U. Leuven, Naamsestraat 61, B-3000 Leuven, Belgium
| | - Marcel Eens
- Behavioural Ecology & Ecophysiology Research Group, Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Rianne Pinxten
- Behavioural Ecology & Ecophysiology Research Group, Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium; Didactica Research Group, Faculty of Social Sciences, University of Antwerp, B-2000 Antwerp, Belgium
| | - Jan Komdeur
- Behavioural and Physiological Ecology, Groningen Institute for ELIFES, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands
| | - Ton G G Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands
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27
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Sexually antagonistic selection during parental care is not generated by a testosterone-related intralocus sexual conflict-insights from full-sib comparisons. Sci Rep 2015; 5:17715. [PMID: 26625951 PMCID: PMC4667218 DOI: 10.1038/srep17715] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 11/04/2015] [Indexed: 01/05/2023] Open
Abstract
The evolution of shared male and female traits can be hampered if selection favours sex-specific optima. However, such genomic conflicts can be resolved when independent male and female mechanisms evolve. The existence, extent and consequences of conflict and/or conflict resolution are currently debated. Endocrinological traits like plasma testosterone (T) are suitable test cases, given their important role in mediating correlated traits, plus their opposing sex-specific fitness effects. We compared full-sibling (brother/sister) captive canaries to test for (1) sexually antagonistic selection characterized by contrasting fitness patterns within pairs of relatives, (2) intersexual genetic correlation of plasma T (h(²) = 0.41 ± 0.31) and (3) intralocus sexual conflict over T levels featured by distinct sex-specific fitness optima. We found potential for sexually antagonistic selection, since high fledgling mass was reached by either brothers or sisters, but not by both. We report a positive intersexual correlation for T, as a requirement for intralocus sexual conflict. However, high levels of T were associated with increased female and decreased male fitness (fledgling mass), which contrasts our expectations and challenges the hypothesis of intralocus sexual conflict driven by T. We hypothesize that behavioural and physiological trade-offs differ between sexes when raising offspring, driving T levels towards a state of monomorphism.
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28
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Ruuskanen S. Hormonally-mediated maternal effects in birds: Lessons from the flycatcher model system. Gen Comp Endocrinol 2015; 224:283-93. [PMID: 26393309 DOI: 10.1016/j.ygcen.2015.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 09/09/2015] [Accepted: 09/17/2015] [Indexed: 11/20/2022]
Abstract
Maternal effects are a crucial mechanism in many taxa in generating phenotypic variation, affecting offspring development and fitness and thereby potentially adapting them to their expected environments. Androgen hormones in bird eggs have attracted considerable interest in past years, and it is frequently assumed that their concentrations in eggs are shaped by Darwinian selection. Currently, however, the data is scattered over species with very different life-history strategies, environments and selection pressures, making it difficult to draw any firm conclusions as to their functional significance for a given system. I review the evidence available as to the function, variation and potential adaptive value of yolk androgens (testosterone, T and androstenedione, A4) using one well-studied wild bird model system, the European flycatchers Ficedula hypoleuca and Ficedula albicollis. These species both show genetic and environmental variation in yolk androgen levels, along with fitness correlations for the female, suggesting the potential for selection. However, variation in yolk T and A4 seem to be differentially affected, suggesting that maternal constraints/costs shape the transfer of the yolk steroids differently. Most of the environmental variation is consistent with the idea of high yolk androgen levels under poor rearing conditions, although the effect sizes in relation to environmental variation are rather small in relation to genetic among-female variation. Importantly, within-clutch patterns too vary in relation to environmental conditions. Yolk androgens seem to have multiple short- and long-term effects on phenotype and behavior; importantly, they are also correlated with the fitness of offspring and mothers. However, the effects are often sex-dependent, and not universally beneficial for the offspring. Unfortunately, conclusive data as to the adaptive benefits of clutch mean androgen levels or within clutch-patterns in different environmental conditions is still lacking.
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Affiliation(s)
- Suvi Ruuskanen
- Section of Ecology, Department of Biology, University of Turku, Finland.
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29
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Groothuis TGG, Taborsky B. Introducing biological realism into the study of developmental plasticity in behaviour. Front Zool 2015; 12 Suppl 1:S6. [PMID: 26816523 PMCID: PMC4722348 DOI: 10.1186/1742-9994-12-s1-s6] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
There is increasing attention for integrating mechanistic and functional approaches to the study of (behavioural) development. As environments are mostly unstable, it is now often assumed that genetic parental information is in many cases not sufficient for offspring to become optimally adapted to the environment and that early environmental cues, either indirectly via the parents or from direct experience, are necessary to prepare them for a specific environment later in life. To study whether these early developmental processes are adaptive and through which mechanism, not only the early environmental cues but also how they impinge on the later-life environmental context has therefore to be taken into account when measuring the animal's performance. We first discuss at the conceptual level six ways in which interactions between influences of different time windows during development may act (consolidation, cumulative information gathering and priming, compensation, buffering, matching and mismatching, context dependent trait expression). In addition we discuss how different environmental factors during the same time window may interact in shaping the phenotype during development. Next we discuss the pros and cons of several experimental designs for testing these interaction effects, highlighting the necessity for full, reciprocal designs and the importance of adjusting the nature and time of manipulation to the animal's adaptive capacity. We then review support for the interaction effects from both theoretical models and animal experiments in different taxa. This demonstrates indeed the existence of interactions at multiple levels, including different environmental factors, different time windows and between generations. As a consequence, development is a life-long, environment-dependent process and therefore manipulating only the early environment without taking interaction effects with other and later environmental influences into account may lead to wrong conclusions and may also explain inconsistent results in the literature.
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Affiliation(s)
- Ton G G Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, Nijenborgh 7, 9747 AG, Groningen, the Netherlands
| | - Barbara Taborsky
- Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50a, 3032 Hinterkappelen, Switzerland
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Okuliarova M, Kankova Z, Bertin A, Leterrier C, Mostl E, Zeman M. Maternally derived egg hormones, antibodies and antimicrobial proteins: common and different pathways of maternal effects in Japanese quail. PLoS One 2014; 9:e112817. [PMID: 25390303 PMCID: PMC4229250 DOI: 10.1371/journal.pone.0112817] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022] Open
Abstract
Avian eggs contain a variety of maternally-derived substances that can influence the development and performance of offspring. The levels of these egg compounds vary in relation to environmental and genetic factors, but little is known about whether there are correlative links between maternal substances in the egg underlying common and different pathways of maternal effects. In the present study, we investigated genetically determined variability and mutually adjusted deposition of sex hormones (testosterone-T, androstenedione-A4 and progesterone-P4), antibodies (IgY) and antimicrobial proteins (lysozyme) in eggs of Japanese quail (Coturnix japonica). We used different genetic lines that were independently selected for yolk T concentrations, duration of tonic immobility and social reinstatement behaviour, since both selections for behavioural traits (fearfulness and social motivation, respectively) produced considerable correlative responses in yolk androgen levels. A higher selection potential was found for increased rather than decreased yolk T concentrations, suggesting that there is a physiological minimum in egg T levels. Line differences in yolk IgY concentrations were manifested within each selection experiment, but no consistent inter-line pattern between yolk IgY and T was revealed. On the other hand, a consistent inverse inter-line pattern was recorded between yolk IgY and P4 in both selections for behavioural traits. In addition, selections for contrasting fearfulness and social motivation were associated with changes in albumen lysozyme concentrations and an inverse inter-line pattern between the deposition of yolk IgY and albumen lysozyme was found in lines selected for the level of social motivation. Thus, our results demonstrate genetically-driven changes in deposition of yolk T, P4, antibodies and albumen lysozyme in the egg. This genetic variability can partially explain mutually adjusted maternal deposition of sex hormones and immune-competent molecules but the inconsistent pattern of inter-line differences across all selections indicates that there are other underlying mechanisms, which require further studies.
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Affiliation(s)
- Monika Okuliarova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
- * E-mail:
| | - Zuzana Kankova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
| | - Aline Bertin
- INRA Val de Loire, UMR 85 Physiologie de la Reproduction et des Comportements CNRS-UMR 7247 - Université de Tours – IFCE, Nouzilly, France
| | - Christine Leterrier
- INRA Val de Loire, UMR 85 Physiologie de la Reproduction et des Comportements CNRS-UMR 7247 - Université de Tours – IFCE, Nouzilly, France
| | - Erich Mostl
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
- Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Ivanka pri Dunaji, Slovak Republic
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Immune responsiveness of Japanese quail selected for egg yolk testosterone content under severe protein restriction. Comp Biochem Physiol A Mol Integr Physiol 2014; 177:41-8. [DOI: 10.1016/j.cbpa.2014.07.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/22/2014] [Accepted: 07/22/2014] [Indexed: 11/23/2022]
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Tschirren B, Postma E, Gustafsson L, Groothuis TGG, Doligez B. Natural selection acts in opposite ways on correlated hormonal mediators of prenatal maternal effects in a wild bird population. Ecol Lett 2014; 17:1310-5. [PMID: 25130200 DOI: 10.1111/ele.12339] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 05/14/2014] [Accepted: 07/16/2014] [Indexed: 11/28/2022]
Abstract
Maternal hormones are important mediators of prenatal maternal effects. Although many experimental studies have demonstrated their potency in shaping offspring phenotypes, we know remarkably little about their adaptive value. Using long-term data on a wild collared flycatcher (Ficedula albicollis) population, we show that natural selection acts in opposite ways on two maternally derived androgens, yolk androstenedione (A4) and yolk testosterone (T). High yolk A4 concentrations are associated with higher fitness, whereas high yolk T concentrations are associated with lower fitness. Natural selection thus favours females that produce eggs with high A4 and low T concentrations. Importantly, however, there exists a positive (non-genetic) correlation between A4 and T, which suggests that females are limited in their ability to reach this adaptive optimum. Thereby, these results provide strong evidence for an adaptive value of differential maternal androgen deposition, and a mechanistic explanation for the maintenance of variation in maternal investment in the wild.
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Affiliation(s)
- Barbara Tschirren
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
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33
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On the coadaptation of offspring begging and parental supply—a within-individual approach across life stages. Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1756-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Aslam MA, Hulst M, Hoving-Bolink RAH, Smits MA, de Vries B, Weites I, Groothuis TGG, Woelders H. Yolk concentrations of hormones and glucose and egg weight and egg dimensions in unincubated chicken eggs, in relation to egg sex and hen body weight. Gen Comp Endocrinol 2013; 187:15-22. [PMID: 23510857 DOI: 10.1016/j.ygcen.2013.02.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 02/13/2013] [Accepted: 02/24/2013] [Indexed: 11/15/2022]
Abstract
Birds can manipulate offspring sex ratio under natural and experimental conditions and maternal hormones have been shown to be involved in this process. Studies also provided evidence for the presence of sex specific concentrations of yolk hormones in avian eggs. These findings led to the suggestion that yolk hormones could influence genetic sex determination in birds. However, in previous studies, yolk hormone concentrations and egg sex were studied in incubated eggs, although incubation of the eggs and embryonic development can alter yolk hormone concentrations and measured sex ratio. This study is the first to determine a wide array of egg components and hen body weight in relation to the sex of the egg in unincubated eggs. Egg parameters studied were yolk concentrations of testosterone, estradiol, androstenedione, progesterone, dihydrotestosterone, and glucose, and egg weight and dimensions. In addition, we studied the associations among all measured parameters. Associations were found between a number of yolk hormones (progesterone associated with testosterone, estradiol and androstenedione; androstenedione with testosterone; dihydrotestosterone with estradiol and androstenedione) as well as between yolk testosterone and egg length and egg weight. There were no significant overall differences between male and female chicken eggs in any of the measured egg parameters. However, there were a few interactions such as the interaction of egg sex with dihydrotestosterone and with hen body weight which predicted estradiol levels and an interaction of estradiol levels with egg width for predicting sex of egg. Their biological relevance need, however, further study.
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Affiliation(s)
- M Aamir Aslam
- Animal Breeding and Genomics Centre, Wageningen UR Livestock Research, PO Box 65, 8200 AB Lelystad, The Netherlands
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Benowitz-Fredericks ZM, Kitaysky AS, Welcker J, Hatch SA. Effects of food availability on yolk androgen deposition in the black-legged kittiwake (Rissa tridactyla), a seabird with facultative brood reduction. PLoS One 2013; 8:e62949. [PMID: 23675443 PMCID: PMC3652864 DOI: 10.1371/journal.pone.0062949] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 03/26/2013] [Indexed: 11/19/2022] Open
Abstract
In birds with facultative brood reduction, survival of the junior chick is thought to be regulated primarily by food availability. In black-legged kittiwakes (Rissa tridactyla) where parents and chicks are provided with unlimited access to supplemental food during the breeding season, brood reduction still occurs and varies interannually. Survival of the junior chick is therefore affected by factors in addition to the amount of food directly available to them. Maternally deposited yolk androgens affect competitive dynamics within a brood, and may be one of the mechanisms by which mothers mediate brood reduction in response to a suite of environmental and physiological cues. The goal of this study was to determine whether food supplementation during the pre-lay period affected patterns of yolk androgen deposition in free-living kittiwakes in two years (2003 and 2004) that varied in natural food availability. Chick survival was measured concurrently in other nests where eggs were not collected. In both years, supplemental feeding increased female investment in eggs by increasing egg mass. First-laid ("A") eggs were heavier but contained less testosterone and androstenedione than second-laid ("B") eggs across years and treatments. Yolk testosterone was higher in 2003 (the year with higher B chick survival) across treatments. The difference in yolk testosterone levels between eggs within a clutch varied among years and treatments such that it was relatively small when B chick experienced the lowest and the highest survival probabilities, and increased with intermediate B chick survival probabilities. The magnitude of testosterone asymmetry in a clutch may allow females to optimize fitness by either predisposing a brood for reduction or facilitating survival of younger chicks.
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Egbert JR, Jackson MF, Rodgers BD, Schwabl H. Between-female variation in house sparrow yolk testosterone concentration is negatively associated with CYP19A1 (aromatase) mRNA expression in ovarian follicles. Gen Comp Endocrinol 2013; 183:53-62. [PMID: 23247271 DOI: 10.1016/j.ygcen.2012.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 11/16/2012] [Accepted: 12/03/2012] [Indexed: 11/16/2022]
Abstract
Maternally-derived yolk androgens influence the development and long-term phenotype of offspring in oviparous species. Between-female variation in the amounts of these yolk androgens has been associated with a number of social and environmental factors, suggesting that the variation is adaptive, but the mechanisms behind it are unknown. Using two different approaches, we tested the hypothesis that variation in yolk androgen levels across individuals is associated with variation in their capacity to synthesize androgens. First, we injected female house sparrows with exogenous gonadotropin-releasing hormone (GnRH) to maximally stimulate ovarian steroidogenesis. Second, we collected pre-ovulatory follicle tissue and quantified the mRNA expression of four key enzymes of the steroid synthesis pathway: steroidogenic acute regulatory protein (StAR), cytochrome P450-side chain cleavage enzyme (CYP11A1), 17β-hydroxysteroid dehydrogenase (HSD17B1), and aromatase (CYP19A1). Thirty minutes after GnRH injection, androgen concentrations in both the plasma and in the yolks of pre-ovulatory follicles were significantly elevated compared to controls. However, this measure of steroidogenic capacity did not explain variation in yolk testosterone levels, although physiological differences between house sparrows and more widely studied poultry models were revealed by this approach. Steroidogenic enzyme mRNA levels were detectable in all samples and were significantly lower in the most mature pre-ovulatory follicles. Of the four measured genes, CYP19A1 expression exhibited a significant negative relationship with yolk testosterone concentrations in laid eggs, revealing a key mechanism for between-female variation in yolk testosterone. Furthermore, this suggests that any factors which alter the expression of CYP19A1 within an individual female could have dramatic effects on offspring phenotype.
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Affiliation(s)
- Jeremy R Egbert
- School of Biological Sciences, Washington State University, WA 99164-4236, United States.
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Muller M, Groothuis TGG. Within-clutch variation in yolk testosterone as an adaptive maternal effect to modulate avian sibling competition: evidence from a comparative study. Am Nat 2012; 181:125-36. [PMID: 23234850 DOI: 10.1086/668601] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In many species, embryos are exposed to maternal hormones in utero, in the egg, or in the seed. In birds, mothers deposit substantial testosterone into their eggs, which enhances competitive ability of offspring. These maternal testosterone concentrations vary systematically within clutches in different patterns and may enable mothers to adaptively fine-tune competitive hierarchies within broods. We performed a comparative analysis to investigate this hypothesis using a broad set of avian species. We expected species with small size differences among siblings (arising from small hatching asynchrony or slow growth rates) to aim for survival of the whole brood in good years and therefore compensate last-hatching eggs with relatively more testosterone. We expected species with large size differences among siblings (large hatching asynchrony or fast growth rates) to produce surplus young as insurance against failed offspring and to facilitate elimination of redundant surplus young by bestowing last-hatching eggs with relatively less testosterone. As predicted, we found that maternal testosterone compensation to last-hatching eggs is stronger when size differences among siblings become smaller. Maternal testosterone compensation to last-hatching eggs also correlated negatively with hatching asynchrony and growth rates. These findings provide evidence for correlated evolution of several maternal effects that together support different maternal reproductive strategies.
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Affiliation(s)
- Martina Muller
- Behavioural Biology, Centre of Behavioural Neurosciences, University of Groningen, The Netherlands.
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38
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Zeman M, Skrobanek P, Okuliarova M. Genetic differences in yolk testosterone levels influence maternal hormone deposition in the second laying cycle in Japanese quails. Comp Biochem Physiol A Mol Integr Physiol 2012; 164:271-5. [PMID: 23103670 DOI: 10.1016/j.cbpa.2012.10.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 10/20/2012] [Accepted: 10/20/2012] [Indexed: 10/27/2022]
Abstract
Maternally-derived yolk androgens exhibit distinct among- and within-female variations but limited data refer to inter-seasonal changes of maternal hormones in the yolk. We investigated the deposition of yolk testosterone (T) across two laying cycles in Japanese quail. To test how genetically-determined differences influence between cycle variations in yolk androgens we compared females from low (LET) and high (HET) egg T lines at the end of the first and at the beginning of the second laying cycle after an induced moult. Line differences in yolk T levels exhibited high consistency exceeding two reproductive cycles. Yolk T concentrations increased in the second laying cycle in HET but not in LET females. Plasma T levels did not differ between cycles in both lines and no line differences were found either before or after the moult indicating the presence of mechanisms limiting the increase of T concentrations in the circulation. Differences in the yolk T levels were not accompanied by changes in the egg and yolk mass. The HET quail laid eggs with heavier eggshell than the LET quail. Our results demonstrate different abilities of mothers to deposit T in their eggs over two reproductive seasons with expected consequences on the development of their progeny.
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Affiliation(s)
- Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
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Müller W, Vergauwen J, Eens M, Blount JD. Environmental effects shape the maternal transfer of carotenoids and vitamin E to the yolk. Front Zool 2012; 9:17. [PMID: 22876878 PMCID: PMC3502133 DOI: 10.1186/1742-9994-9-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 08/03/2012] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED INTRODUCTION Maternal effects occur when the phenotype of the offspring is influenced by the phenotype of the mother, which in turn depends on her heritable state as well as on influences from the current and past environmental conditions. All of these pathways may, therefore, form significant sources of variation in maternal effects. Here, we focused on the maternal transfer of carotenoids and vitamin E to the egg yolk, using canaries as a model species. Maternal yolk carotenoids and vitamin E are known to generate significant phenotypic variation in offspring, representing examples of maternal effects. We studied the intra-individual consistency in deposition patterns across two years and the mother-daughter resemblance across two generations in order to estimate the level of heritable variation. The effects of the current environmental conditions were studied via a food supplementation experiment, while the consequences of past environmental conditions were estimated on the basis of the early growth trajectories. RESULTS There was a significant effect of the current environmental conditions on the yolk carotenoid and vitamin E deposition, but this effect varied between antioxidant components. The deposition of yolk carotenoids and vitamin E were linked to the process of yolk formation. Past environmental conditions did not contribute to the variation in yolk carotenoid and vitamin E levels nor did we find significant heritable variation. CONCLUSIONS The transfer of carotenoids or vitamin E may be an example where current environmental variation is largely passed from the mother to the offspring, despite the numerous intermediate physiological steps that are involved. Differences in the effect of the environmental conditions as experienced by the mother during laying may be due to differences in availability as well as physiological processes such as competitive exclusion or selective absorption.
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Affiliation(s)
- Wendt Müller
- Department of Biology-Ethology, University of Antwerp, 2610, Wilrijk, Belgium.
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Kankova Z, Zeman M, Okuliarova M. Growth and innate immunity are not limited by selection for high egg testosterone content in Japanese quail. ACTA ACUST UNITED AC 2012; 215:617-22. [PMID: 22279068 DOI: 10.1242/jeb.064030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effects of maternal androgens on fitness-related traits of offspring are generally assumed to be epigenetic adaptations to the environment that may be encountered by the next generation. Possible constraints of high yolk androgen transfer are still not understood, although a suppressed immune response in offspring is frequently considered. The aim of our study was to examine the innate immune defence in high (HET) and low egg testosterone (LET) lines of Japanese quail, which differ in the hormonal milieu of their eggs, thus providing a good physiological model for the study of androgen-mediated maternal effects. Acute phase response was induced by a lipopolysaccharide injection in 12-day-old quail and plasma corticosterone and the heterophil:lymphocyte ratio were measured at 1 and 3 h post-treatment. Basal levels of non-specific antibodies (IgY) were determined in the circulation. We found that HET quail were heavier than LET quail from the second week of age, indicating enhanced post-hatching growth. At 1 h post-lipopolysaccharide challenge, plasma corticosterone concentrations increased in the HET but not in the LET line. The heterophil:lymphocyte ratio rose in both lines at 3 h post-immune challenge, with a more pronounced response in HET quail. Moreover, HET chicks displayed higher IgY levels than LET chicks, suggesting either enhanced passive immunoprotection or stimulated endogenous antibody production. In conclusion, our data demonstrate that the genetic selection for high egg testosterone content positively influences growth and, simultaneously, does not limit the acute phase response in young quail.
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Affiliation(s)
- Zuzana Kankova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
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Coslovsky M, Groothuis T, de Vries B, Richner H. Maternal steroids in egg yolk as a pathway to translate predation risk to offspring: experiments with great tits. Gen Comp Endocrinol 2012; 176:211-4. [PMID: 22326354 DOI: 10.1016/j.ygcen.2012.01.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 01/17/2012] [Accepted: 01/22/2012] [Indexed: 10/14/2022]
Abstract
Exposure of mothers to risk of predation can induce phenotypic changes in offspring as shown in several species. We previously found that cross-fostered great tit (Parus major) chicks of females exposed to increased predation risk were smaller and lighter, but had faster wing growth than control cross-fostered chicks, possibly improving predator-escaping abilities. Here we examined the possible role of maternal steroids deposited in eggs as an underlying mechanism. We collected eggs from female great tits under either experimentally increased predation risk (PRED) or control treatments (CON) and analyzed the concentration of testosterone, androstenedione, and progesterone in the yolks. PRED eggs contained lower levels of testosterone than CON eggs, but levels of androstenedione and progesterone did not differ. The smaller size and mass of chicks found in the previous study may thus be explained by the lower testosterone concentrations, since yolk testosterone is known to boost growth and development. Alternatively, testosterone may act as a modulator of differential investment into morphological traits, rather than a simple growth enhancer, explaining lower body mass in conjunction with the accelerated wing growth. This could possibly occur concurrently with other hormones such as corticosterone.
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Affiliation(s)
- Michael Coslovsky
- Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland.
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Müller W, Goerlich VC, Vergauwen J, Groothuis TGG, Eens M. Sources of variation in yolk hormone deposition: consistency, inheritance and developmental effects. Gen Comp Endocrinol 2012; 175:337-43. [PMID: 22146794 DOI: 10.1016/j.ygcen.2011.11.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 10/25/2011] [Accepted: 11/21/2011] [Indexed: 10/15/2022]
Abstract
Maternal effects occur when the phenotype of the mother affects the phenotype of their offspring. They are thought to have evolved to translate the environmental conditions experienced by the mother into adaptive phenotypic variation of the offspring. However, the integration of environmental cues allowing adaptive responses requires some form of plasticity that depends on the interaction of the maternal phenotype and her environment. In birds, maternal yolk hormones represent such a pathway for maternal effects, and their adaptive significance depends thus on the plasticity in maternal yolk hormone deposition. We studied sources of variation in yolk testosterone deposition, focusing on the often neglected contribution of the (partly heritable) maternal phenotype. We investigated consistency and heritability of yolk testosterone deposition in captive canaries of which the F(1) generation was raised in foster nests and analyzed the potential effects of the early developmental conditions. We found significant female consistency across years in egg mass, yolk mass and total amount of yolk testosterone but not in yolk testosterone concentrations. Females varied the yolk testosterone concentrations of their eggs across years mainly via changes in yolk mass. The heritable variation in egg mass, yolk mass and amount of yolk testosterone but not yolk testosterone concentrations was within the range of previous studies, but not significantly different from zero. Finally, the growth of the daughters as nestling had a significant effect on their yolk testosterone deposition at adulthood indicating the transgenerational potential for environmental effects - via the effects of yolk hormones on offspring development.
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Affiliation(s)
- Wendt Müller
- Department of Biology-Ethology, University of Antwerp, Belgium.
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Elevated plasma corticosterone decreases yolk testosterone and progesterone in chickens: linking maternal stress and hormone-mediated maternal effects. PLoS One 2011; 6:e23824. [PMID: 21886826 PMCID: PMC3160319 DOI: 10.1371/journal.pone.0023824] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 07/27/2011] [Indexed: 12/26/2022] Open
Abstract
Despite considerable research on hormone-mediated maternal effects in birds, the underlying physiology remains poorly understood. This study investigated a potential regulation mechanism for differential accumulation of gonadal hormones in bird eggs. Across vertebrates, glucocorticoids can suppress reproduction by downregulating gonadal hormones. Using the chicken as a model species, we therefore tested whether elevated levels of plasma corticosterone in female birds influence the production of gonadal steroids by the ovarian follicles and thus the amount of reproductive hormones in the egg yolk. Adult laying hens of two different strains (ISA brown and white Leghorn) were implanted subcutaneously with corticosterone pellets that elevated plasma corticosterone concentrations over a period of nine days. Steroid hormones were subsequently quantified in plasma and yolk. Corticosterone-implanted hens of both strains had lower plasma progesterone and testosterone levels and their yolks contained less progesterone and testosterone. The treatment also reduced egg and yolk mass. Plasma estrogen concentrations decreased in white Leghorns only whereas in both strains yolk estrogens were unaffected. Our results demonstrate for the first time that maternal plasma corticosterone levels influence reproductive hormone concentrations in the yolk. Maternal corticosterone could therefore mediate environmentally induced changes in yolk gonadal hormone concentrations. In addition, stressful situations experienced by the bird mother might affect the offspring via reduced amounts of reproductive hormones present in the egg as well as available nutrients for the embryo.
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Okuliarova M, Kostal L, Zeman M. Effects of divergent selection for yolk testosterone content on growth characteristics of Japanese quail. Comp Biochem Physiol A Mol Integr Physiol 2011; 160:81-6. [PMID: 21627997 DOI: 10.1016/j.cbpa.2011.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/13/2011] [Accepted: 05/13/2011] [Indexed: 10/18/2022]
Abstract
Effects of yolk androgens on postnatal growth of offspring have been widely studied but their physiological role in the growth control is not fully understood due to an inconsistency in obtained results. We investigated androgen-mediated maternal effects on postnatal growth in relation to endocrine control mechanisms using two lines of Japanese quail divergently selected for high (HET) and low (LET) egg testosterone (T) content. Embryonic growth did not differ between the lines. During the growth period HET quail were heavier and displayed longer tarsi as compared with LET quail, with more pronounced line differences in males than females. HET males were heavier than LET males from the age of 2 weeks, reached the age of maximum growth rate earlier, and displayed higher asymptotic body weight than LET males. Accelerated growth in HET males was not accompanied by increased postembryonic plasma T concentrations. Plasma triiodothyronine levels did not differ between lines while plasma thyroxine levels were decreased in HET as compared with LET female chicks. Line differences in body weight disappeared in adult quail suggesting that yolk androgens, increased in a physiological way, resulted in stimulation of juvenile growth rate in precocial Japanese quail under stable social and environmental conditions.
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Affiliation(s)
- Monika Okuliarova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
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